Ferroelectric domain structure in epitaxial BiFeO3 films

Abstract

Piezoelectric force microscopy is employed to study the ferroelectric domain structure in a 600nm thick epitaxial BiFeO3 film. In the as-grown film, a mosaic-like domain structure is observed. Scans taken with the cantilever pointing along the principal crystallographic directions enabled us to reconstruct the polarization direction. By combining the perpendicular and in-plane piezoresponse data, we found that the ferroelectric domain structure is mainly described by four polarization directions. These directions point oppositely along two body diagonals, which form an angle of ∼71°. The other variants are also occasionally observed.

Shear effects in lateral piezoresponse force microscopy at 180° ferroelectric domain walls

“…22 Having considered the d 35 DW response in materials with a purely out-of-plane polarization, we next addressed its effects on PFM measurements in BFO thin films deposited on ͑001͒ SrTiO 3 , which present a monoclinically distorted tetragonal structure with polarization lying close to the ͗111͘ directions. 23,24 In these films, due to the lower symmetry and finite in-plane component of the polarization, the d 35 coefficient ͑d 35 m ͒ is expected to be nonzero even in uniformlypolarized regions. To correctly characterize these films it is thus necessary to differentiate between any shear effect at the domain walls, and the actual in-plane polarization.…”

Fractal Dimension and Size Scaling of Domains in Thin Films of MultiferroicBiFeO3

“…Its lead-free nature and large remanent polarization [4] have already motivated Fujitsu to use it as the active layer in prototype ferroelectric memories [5]; also, sublattice magnetic switching using voltage has been demonstrated [6], which may find its way into spintronic applications via exchange bias [7]. The possible coupling between ferroelectric and antiferromagnetic domains has triggered a flurry of work on the morphology and functional properties of the domains [6,[8][9][10][11]. Standard BFO films are generally found to have straightwalled domains which follow the well-known scaling law of Landau, Lifshitz, and Kittel (LLK) [12 -14], that is, domain width grows proportionally to the square root of film thickness [10].…”

Room temperature magnetic-field manipulation of electrical polarization in multiferroic thin film compositeBiFeO3∕La2∕3Cheng1, Wang2 2007Phys. Rev. B63180View full textAdd to dashboardCite

“…[16][17][18][19] Besides all the achievements that have occurred in terms of materials processing techniques, another important achievement is the direct observation of the electrical control of antiferromagnetic domains in epitaxially grown BiFeO 3 films on STO at room temperature. [20][21][22] Using piezoforce microscopy and x-ray photoemission electron microscopy, high-resolution images of both antiferromagnetic and ferroelectric domain structures of ͑001͒-oriented BiFeO 3 films were detected. 20 A clear correlation was observed between the ferroelectric and antiferromagnetic domains, indicating a strong coupling between the two types of order.…”